1. Technical Field
The apparatus of the present invention relates generally to slingshots. More specifically, it relates to an apparatus for achieving a greater shot-to-shot release uniformity and velocity consistency and hence a greater accuracy. The invention also relates to a sighting apparatus used in conjunction with the slingshot which enables a more accurate sighting of the target.
Currently, most slingshot devices are adapted to be held by one hand and the projectile pouch retracted with the other hand. These devices have extremely large inaccuracies due to the inconsistent shot-to-shot release.
Since the initial velocity, at the point of release, is directly related to the tension in the elastic band at the time of release, it is also clear that these devices suffer from a great shot-to-shot inconsistency of initial velocity due to the inequality of tension placed on the elastic band. Consequently, in the interest of increasing accuracy, it is highly desirable to provide a slingshot apparatus wherein the initial velocity can be consistently maintained from one firing to the next.
2. Description of the Prior Art
Currently, prior art slingshot devices come in one of three typical embodiments. First is the simple hand-held "Y"-shaped stick. The second conventional configuration consists of a slingshot having a design similar to the first mentioned configuration but also having an additional wrist bar adapted to provide stability to the slingshot when the elastic band is being extended. In both of these first two conventional embodiments, the elastic band imparting the initial velocity to the projectile, is extended with the fingers of the operator's free hand. As is well understood in the art, these methods have a great targeting inaccuracy associated therewith due to the shot-to-shot inconsistency of release.
As also known in the art, the key to accuracy when using a slingshot apparatus is a consistent shot-to-shot initial velocity. In a slingshot, the initial velocity is determined by the amount of tension on the elastic band at the time of release. Furthermore, the amount of tension on the elastic band is directly proportional to the distance the band is extended. Thus, if the band is extended a consistent amount from one shot to the next, there is a high probability that the initial velocity will be the same from one shot to the next. A second factor, somewhat related to the first, is the manner in which the band is retracted and more importantly, the manner in which it is released.
Ideally, the elastic band would be extended, held, and released from a single point positioned precisely at the center of the band. Any deviation from a point release results in an uneven release sequence, meaning that some portion of the band is released earlier than some other point. Clearly, this results in some inaccuracies in that the initial projectile vector is not consistent. A third significant factor in accuracy involves the method used to sight the target.
As is well understood in the laws of physics, any object falling in the earth's gravitational field will have a downwardly directed acceleration vector of 32 feet per second, squared. Thus, based on a given amount of time, the vertical displacement of a object may be determined relative to its initial position. If the projectile is also given an initial horizontal velocity vector, its final position may be determined based on knowledge of this initial velocity vector and the elapsed time. A sight may be used to predict the impact point based on an alignment of a forward and rearward sighting points. It is highly desirable for this sighting mechanism to be positioned above the departure path, defined as the initial horizontal velocity vector of the projectile, so that the distance to the final trajectory impact point is maximized. It is clear to those in the art that such sighting considerations are especially important since the slingshot is a low velocity weapon.
A third conventional slingshot apparatus embodiment attempts to remove some of the shot-to-shot inconsistencies inherent in the completely manual embodiments discussed above. This third conventional embodiment is typified by the Kees U.S. Pat. Nos. 4,784,106 and 4,593,673 and Burghardt U.S. Pat. No. 3,857,379. In both of these patents, the elastic band is extended to the stretched position by a mechanical means. The slingshot may be released by a trigger mechanism disengaging the locking means which retains the elastic band in the extended, cocked position. In all three of these devices, the elastic band is mounted in the horizontal plane. This horizontal mounting of the elastic band presents severe problems regarding the sighting mechanism used or prevents the installation of a sighting mechanism altogether. For example, the Burghardt device is completely lacking in any type of sighting device. It is clear that if a sighting member is to be used with a device having a horizontally oriented elastic band, it will either have to be offset from the initial horizontal departure vector or it will necessarily need to be sighted below the horizontal departure plane. Otherwise, if the designer attempts to place the sighting mechanism in vertical alignment with the projectile pouch and in approximately the same horizontal departure plane, the sighting means will present an obstacle to the departure of the projectile. One attempted solution to this problem in Kees was to provide a flexible latex rubber sighting member as the forward sight.
The flexibility of the forward sight was designed to permit the projectile to pass freely thereby without disturbing its flight path even if it should contact the sighting member. However, clearly any physical contact by the projectile with the sighting member is going to alter the projectile's flight trajectory and thereby disturb the targeting accuracy. Conversely, if the sighting mechanism is placed below the projectile departure plane, the target distance is necessarily limited due to the flight trajectory of the projectile as described in more detail below.
Consequently, it is a primary objective of the present invention to provide an enhanced accuracy slingshot apparatus wherein the elastic bands are oriented vertically such that the sighting means may be placed above and in alignment with the departure vector so as to enhance the overall accuracy of the device while providing a maximum targeting distance.
Another objective is to provide an improved accuracy slingshot apparatus wherein the release mechanism is operative to secure and release the projectile pouch from as nearly a single point of contact as possible so as to facilitate a uniform release or initial projectile vector.
Another objective is to provide an improved accuracy slingshot apparatus wherein the degree of tension on the elastic band in the extended, cocked position may be adjusted.
Another objective of the improved accuracy slingshot apparatus of the present invention is to provide a device wherein the elastic band may be maintained in a retracted, holding position awaiting cocking of the apparatus wherein the elastic band is just slightly taut, thereby preventing any excess stretching of the band between shots.
Another objective of the present invention is to provide a sighting means which is positioned above and in vertical alignment with the line of departure for the projectile, thereby increasing its effective range.
A further objective of the present invention is to provide an improved accuracy slingshot apparatus wherein a sighting means may be employed having a plurality of sighting apertures corresponding to a plurality of terminal target distances.
A further objective of the present invention is to provide an improved accuracy slingshot apparatus maximizing the shot-to-shot consistency of the projectile initial velocity.
Another objective of the present invention is to provide an apparatus wherein the handgrips of the apparatus may be adjusted to accommodate the arm lengths of different individuals.